标题： ε_K 在顶夸克时代的现象学 显示英文标题

标题： Phenomenology of epsilon_K in the top era

摘要： 今天的关于单位三角形形状的关键信息来自于对epsilon_K的精确测量，该量表征了|Delta S|=2跃迁中的CP破坏。 现象学分析需要四个关键量的输入：CKM元素V_cb和V_ub的大小，顶夸克质量以及非微扰参数B_K。 近年来，所有这些量都已以越来越高的精度确定。 为了跟上这一进展，必须在重整化群改进的微扰理论的下一阶（NLO）中获得|Delta S|=2哈密顿量。 我将介绍由斯特凡·赫里奇和我计算的QCD系数eta_1和eta_3的NLO结果，并简要描述计算的一些方面。 然后我将使用1996年夏季数据更新单位三角形。 改进的Wolfenstein参数rho-bar和eta-bar以及CKM相位delta的结果为-0.21 < rho-bar < 0.22，0.27 < eta-bar < 0.43和57度 < delta < 122度。 进入B衰变中CP不对称性的量sin(2 beta)的范围为0.46 < sin(2 beta) < 0.79。 给出的范围对应于输入参数的一个标准偏差。 最后我简要讨论K_L-K_S质量差。 显示英文摘要

摘要： Todays key information on the shape of the unitarity triangle is obtained from the well-measured quantity epsilon_K characterizing the CP-violation in |Delta S|=2 transitions. The phenomenological analysis requires the input of four key quantities: The magnitudes of the CKM elements V_cb and V_ub, the top quark mass and the non-perturbative parameter B_K. In the recent years all of them have been determined with increasing precision. In order to keep up with this progress the |Delta S|=2-hamiltonian had to be obtained in the next-to-leading order (NLO) of renormalization group improved perturbation theory. I present the NLO results for the QCD coefficients eta_1 and eta_3, which have been calculated by Stefan Herrlich and myself, and briefly sketch some aspects of the calculation. Then I give an update of the Unitarity Triangle using the summer 1996 data for the input parameters. The results for the improved Wolfenstein parameters rho-bar and eta-bar and the CKM phase delta are -0.21 < rho-bar < 0.22, 0.27 < eta-bar < 0.43 and 57 degrees < delta < 122 degrees. The range for the quantity sin(2 beta) entering CP asymmetries in B-decays is found as 0.46 < sin(2 beta) < 0.79. The given ranges correspond to one standard deviation in the input parameters. Finally I briefly discuss the K_L-K_S mass difference.